1. Rat renal lymph contains immunoreactive glandular kallikrein which does not appear to be biologically active. Lymph also contains high levels of renin and low levels of angiotensin converting enzyme which appear to be the only kinase in lymph. In addition, pooled lymph contains very high levels of trypsin inhibitor(s) and lower levels of kallikrein inhibitors. 2. Rat renal kallidrein is present in high levels in the outer cortex and decreases from outer cortex to inner medulla. 3. Whole human saliva contains kininogen antigens. Levels in parotid saliva are much lower. 4. Parotid salivary kallikrein is elevated in patients with aldosterone-producing tumors and returns to normal upon removal of the tumor.